Gold Nanoparticles Synthesis Using Stainless Steel as Solid Reductant: A Critical Overview

Abstract

Gold nanoparticles (AuNPs) were produced using stainless steel as a solid reductant to assist the synthesis of metal NPs, using HAuCl4 as a precursor. This method is very easy, quick, and cost-effective, allowing the synthesis of highly stable NPs without additional capping agents. However, the reaction mechanism is still under debate. In order to contribute to the investigation of the synthesis of AuNPs using stainless steel, different experimental conditions were tested. Cl− concentration, pH of the precursor solution, as well as stainless steel composition were systematically changed. The syntheses were performed recording the open circuit potential to potentiometrically explore the electrochemical properties of the system, under operando conditions. Spectroscopic and morphological characterizations were carried out along with potentiometric monitoring, aiming at correlating the synthesis parameters with the AuNPs characteristics. As a result, an overview of the process features, and of its most reasonable mechanism were obtained.

Enzyme based field effect transistor: State‐of‐the‐art and future perspectives

“…[60] To this extent, many nanomaterials, both carbon-based nanomaterials (e.g., multiwalled carbon nanotubes, [61][62][63] reduced graphene, etc.) and metal/metal oxide-based nanoparticles [64][65][66] have been used to develop external gate electrodes that exhibited a pH sensitivity by means of potentiometric measurements. [67][68][69] In this regard, Yin et al reported on the development of an H + ion-sensitive EG-FET by using an indium tin oxide (ITO) electrode modified with tin oxide (SnO 2 ) by a sputtering method.…”

“…[ 60 ] To this extent, many nanomaterials, both carbon‐based nanomaterials (e.g., multiwalled carbon nanotubes, [ 61–63 ] reduced graphene, etc.) and metal/metal oxide‐based nanoparticles [ 64–66 ] have been used to develop external gate electrodes that exhibited a pH sensitivity by means of potentiometric measurements. [ 67–69 ] In this regard, Yin et al.…”